Magnetic device for telephone systems.



W. W. DEAN.

MAGNETIC DEVIGE FOB TELEPHONE SYSTEMS.

APPLIUATION FILED JAN. 6, 1904.

Patented Apr. 6, 1909.

l fUNITED;STA1 1 S &TENT onrron ing'is specification.

T 0 all whom it may concern:

the cord circuits are not in use and to close.

number of contacts to only one set. accomplished in my present invention ,by including the magnets of the heretofore sepa- WILLIAM W. D EANQOF CHICAGO, ILLINOIS, ASSIGNOR TO KELLOGG'SWITCHBOARD liNl) SIZBPLY COMPANY, OFv CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

MAGNETIC DEVICE FOR, 'rELEPnoNE'sYsTEi/rs.

Specification/ of Letters Patent.

'. Patented April 6, 190:9. v f

1904'. Serial No.'187,908

Be it known that I, WILLIA W. DEAN, a citizen of the United States of America, and i resident of Chicago, in the county of (look and State of Illinois, have invented a new and useful Improvement in hiagneticDevices 5 for Telephone Systems, oiwhich the follow- I My invention relates to supervisory apparatus for telephone lines.

It has heretofore. been common, in connection with supervisory systems for telephone lines, particularly in such systems as required only two strands in the cord circuit, to provide a pair oi relays for each end of the cord circuit, one of said relays being adapted to normally open the circuit of the siu'iervisory signal to prevent the same from lighting when the circuit of said signal when'the corresponding plug is connected with the subscribers line. The s, .cond relay is ordinarily arranged to open tl circuit of the supervisory signal when'eyer current is flowing over the telephone ling so that said signal is lighted only during til time that the plug is connected with the telephone line and the subscribers telephone is not in use The provision of a pair o'f relays of this type requires a set of contacts for each relay, as well as the individual relays themselves. Such'contacts are made of platinum, which is expensive, and each set of contacts is liable to get out of order through the collection of dust or through the constant sparking that occurs at them.

' The object of my present invention is to reduce not only the number of the individual apparatuses but to reduce the number of contacts required for each set of relays or mag- 1 nets, and more particularly to reduce the This is rate relays in a slngle inte ral structure and to'provide a single set oi contacts for the armatures of said magnets, whereby when the one magnet is energized a circuit is completed through the'setof contacts and when the other magnet is'energized the. said contacts are opened to thus open the said circuit.' Under normal conditions also when both magnetsare deenergized, the said set of contactsgis 03611. This arrangement results samewith the cover in section.

in a considerable saving in apparatus and My invention is illustrated l panying drawing in which the same reference characters are usedthroughout, and in winch:

Figure l is a diagram of a telephone system showing a cord 011'C111l11)l0\*1(l8(l with supervisory apparatus embodying my invencontacts with a consepuent saving iirinitial tion; Fig. is a sectional view of the supervisory relay, and Fig. 3 is a front view ofthe Referring'iirst to Fig. 1, L and L indicate two telephone lines extending; in two limbs .2 and 3 from their'respective substations to the central oifice Where they are fitted with the usual line signal S and a plurality of multiple acks J, J and J 3 in any desired number, ac

cording to the size of the switchboard. .1 line relay R controlling throu h its normally open contacts the local circuit of the line signal S is included in the normal connection of the line conductor-3 with the battery lead 4 extending to the live pole of the central common battery 3, while the other line con' ductor 2 is normally grounded. relay R is vlegged to ground from the sleeve s1de. of the. jack section of the line and-is- A cut-off adapted when energized to disconnectlsaidv line conductors 2- and 3 from their normal connections and connect them with corresponding sides of the jack section of the telephone line. v

At the substation a signaling hell 5 and a condenser 6 are included in abridge of the line conductors that is normally closed by the switch-hook 7, while a transmitter 8, a receiver and a retardation coil 10 are adapt ed to be suitably connected in circuit with i said condenser, 6, when the receive-i. Q-is lifted from the switch-hook 7. This apparatus, however, is intended merely to typify any usual or desired common battery subscribers outfit. 1

At the central. oiiice each operator is;

provided with a plurality of cord circuits,

usually 10 or 12 in number, each'having an answering plug P and a calling plug I provided with tip and sleeve contacts. adapted to register with the correspondingcontacts of the spring jacks when insertedtherein.

The tip cont-acts of the plugs are united through the flexible strands t and t and the interposed condenser a, while their sleeve contacts 'are'simila'rly joined by the strands s and s and the interposed condenser The supervisory apparatus associated with each plug isonly diagrammatically indicated in this figure, and consists of magnets 11 and 12, connected respectively between the tip and sleeve strands of the cord circuit and The magnet 12 is provided with an armature the adjacent poles-of the batteries-B or B i armature 17 of the magnet 11, but when the magnet; 12 is energized the said contact 15 is brought into engagement with the contact v 16 of the armature 17. The adjustment of these parts is such that when the magnet .12 is energized, contact 15 moves forwardly and engages contact 16 but such contact 15v is limited in itsforward movement so that when the magnet 11 is energized the contact 16 is drawn a way fromthe contact 15. and

.hlitiiGOllh-ztC-hg are again separated. An apparatus of this type is provided for each end of the cord circuit, that associated with the answering plug P serving to control the local circuit (if-the supervisory signal S while that associated with the calling plug P similarly controls the local circuit of the supervisory signal S assigned to said plug;

relay is shown. in vFigs. '2 and-3, and consists :vided with two holes, in one of which the magnet 12is placed and in the other of which the magnet 11 is located. These magnets have suitable terminals 19" projecting through the rear of the shell 18. The core 20 of each magnet is secured in place by the set screw-21 and together with the shell 18 form the stationary parts of the magnetic circuit of the magnets. The armature 13 of the 7 magnet 12 is pivoted upon the pin 22- at its lower end and the contact spring 14 is secured thereto but is insulated therefrom by a suitable insulating strip'23. The spring 14 is connected by means of a flexible wire 24 with a terminal wire 25 extending back through the shell 18 to the rear of the casing where it is provided with a suitable terminal 26 to which to connect the conductor of the electrical circuit; said wire 25 is insulated A threaded stud 27 projecting from the forward end of the core 20 of the magnet 12 passes through an enlarged aperture in the armature 13 and is provided with a nut 28 upon the outer side of the armature 13 which acts as a stop for said armature in its normal position. The contact 15 is carried upon the end of the contact spring 14, which spring is preferably turned at right angles as indi- The Ine-' chamcal construct1on of this supervisory cated in Fig. 3. Contact 16 is mounted in a su1table manner upon the armature 17 of themagnet 11, which armature is pivoted upon a suitable pin 29 secured to the shell 18. A threaded stud 30 projecting from the end of the core 20 together with a nut 31 upon the outer side of the armature 17 serves as a stop for said latter'armature. The contact 16 and the armature 17 are not insulated from the shell 18 and to complete the circuit of the lnstrument said shell may be provided with a suitable terminal such as 32 to which the conductor of the circuit may be i'eadilv connected. With this arrangement it is evident that when the magnet 12 is energized its armature 13 will be attracted and the contact 15 upon the spring 14 will engage the contact 16 of armature 17. The movementof the armature 13 is so adjusted in any desired way that it cannot close the arma ture 17 of the magnet 11, which consequently may be drawnaway by the energization of the magnet 11 so as to again separate the contact 16 from the contact .15, even though the magnet 12 remains energized A suitable cover 53 iiiay b' provided f r .the forward end bf the relay to inclose the armatures and theircontacts and may be secured inplace by set screws 34. While only onerelay is shown in igs. 2 and 3, it is ap arent that the bar 18 may be of considera le length and that rows of holes may be provided therein to accommodate a plurality of such apparatus in which case the cover 33 would be enlarged to cover the ion. Ward ends of all of the relays in the bar.

The 0 eration of the a paratus. will now. be readi y understood. ssuming that the subscriber upon the line L takes up his receiver to call the central office, currenti lcfv flows from the battery 13' through the line relay R, over the line conductor 3 and with return through tlfie grounded conductor 2, thus operating t e ine relay R and consequently' the line'signal S. -Upon observing the signal, the' operator inserts the answering lug P of the cord circuit in the answering jack J of the telephone line, and depresses her listening key to connect her head telephone together with the second ary of her induction 36 and a suitable condenser c inja bridge of the calling end of the said cord circuit. j' The insertion of this plug completes path for current from the live pole of the battery 13 through the winding of the magnet 12, strand 8 of the cord circuit and over the sleeve side of the jack'section of the telephone line, through the winding of the cu t-ofi' relay R to ground. Current in this path actuates said cut-off 1125 relay thereby, rendering the line signal inoperative and; to complete connection between the external and switchboard sections of the said line. At the same time the magnet 12 is energized to close the local 13 45 relay R to ground.

the armature 17 of the same and separating the contact 16jfrom contact 15 to open the circuit of said supervisory signal and preventits' operation. U on learning the order of the, subscrib er, whici we will assume to be the l' neL", thesaid line is tested bytouchmg tliefjtiprot' thetcalling plug to the test ring of the jack of that line in the usual manner.

If the line'is idle, no flow of current results since boththe test rings and the tip of the testing plug are at thesani'e' potential, but if the lmeis-connectedfor use, said test rings Tare at avdifl'erent potential due to their conthrough nection with thelive ole of either the battery B or B ithrougi the medium of the sleeve'strand of the inserted lug, and consequently a flow of current ta *es place over the strand t of'the cord circuit, thus causing a surge of current through the operators receiver to indicate'to her that the line is busy. Assuming that the-line is found idle the calling lug P is inserted in one of the multiple jac s andthe ringing key 38 is depressed. The operation of this key czrngenerator 39 with the rip strand of the cord circuit which sends ringing current out. over the telephone line andthe call l: ell 5 of the wanted station, whilent the same time current from the hat- 5 tery B flows out over the battery lead 4 called but and through. the branch conductor 40 and the sleeve spring of said ringing key 38,

through the cut-ofl' relay R of the called line to maintain the same actuated during ringing. After the sulscriber has been before his response current from the battery B is flowing tl'irough the magnet 12 of the supervisory relay associated with the calling plug P and through the cut-oif Current in this path suffices to actuate the magnet 12 and to cause its contact 15 to engage contact 16 of the magnet 11 and since the latter magnet is not yet energized the local circuit of the supervisory signal S is now closed and said signal is lighted to indicate the fact of the non-response of the called subscriber to the o erator. \Vhen the subscriber responds to his call, current ispermitted to (low fr m the battery B through the metallic line with return through said magnet 11 tllelliiy attracting its armature 17 and \vitlulrawing its contact 16 from contact 15, thus opening the local circuit of the signal S and retiring the same.

Attlie termination of the conversation when the subscribers return their receivers to the hooks current is no longer permitted to flow over the telephone lines so that the line and through the magnet 11 as well, to therebytenergize said magnet and attract tegral inclosing shell having a magnets 11 are v dencrgized and the contacts v 16 are again brought into en 'agement with contacts-l5 thereby lighting-t e supervisory signals S and S. Upon observing these zignals the o eratorwithdraws the plugs P and P there v cutting off current from the magnets 12 of the supervisory relays which permit the contacts 1 to separate from contact l6 andretrirn to normal position thus again operiing'tbe circuit ofthe supervisory tiredwhen the cord circuit is not in use.

With this apparatus, but one contact is required for the supervisory device at each end of the cord circuit, and magnet 11 is not re quired to over-power the attractive force of magnet 12 before the circuit of the signal can be opened. v

While I have thus described a particular telephone system with which my inventionis-ada ted to operate, it is to be understood that do'not wish to be limited thereto nor do I wish to be unduly limited to the details of the magnetic device itself, many nunlifications of which would be p ossible'witlmut'departing from the spirit or scope of my invention.

I claim 1. In a relay, the combination with apair of parallel coils, of apair of armatures, one for each of said coils mounted at the end thereof, a contact carried upon one of said armatures, an extension carried upon the other of said armatures having a contact thereon adapted to register with the first contact, said contacts being adapted to be closed when one of the relays is actuated and open when both of said relays are actuated, substantially as described,

2. In a relay, the combination with an insignals 3' and S which are accordingly. re-

tegral inclosing shell having a air of parallel openingstherem, a pair of e ectrornagnets, one within each of said openings, a pair of armatures hinged to said inclpsing shell and res ectively held in ositions, one before the en of each of said e ectromagnets, a contact carried by one of said armatures, an extension upon the other of said armatures, a-contact carried by said extension, said air of contacts being adapted to be closed by the actuation of the latter armature and again opened by the actuation of the former armsture, substantially as described. 3. In a relay, the combination with an inair of parallel openings therein, a pair of e ectromagnets, one within each of said openings, a pair of armatureshinged to said inclosing shell and res ectively held in positions, one before the en of each of said electromagnets, a contact carried directly upon one of said armatures, an extension earned by the other armature and insulated therefrom, a contact carried upon said extension, said air of contacts being adapted to be closed y the actuation of the latter armature and again opened by the actuation of the former armature, sub-- stantially as described.

' dust cap adapted to mclose the armatures and contacts, substantially as described.

5. In a relay, the combination With a pair of parallel electro-magnets, of'armatures located opposite one end of each of said magnets, cooperating contacts carried by said armatures, the contact of one armature being adapted to be drawn against the contact of the other when the first armature is actuated, and the contact of the second armature being adapted to be drawn away from the first when the second'armature is actuated, substantially as described.

6. In a-relay, the combination With a pair magnetic circuit thereof, a pair of armatures' sup orted by the shell, one before each of 'SSJIC electromagnets," contacts carried by said armatures adapted to connect with eac other upon the actuation of one of the armatures and to beagain disconnected upon the actuation of both of the armatures, substantially as described. v

7. In a relay, the combination with a pair of parallel electro magnets, of an armature located at the end ofeach of said ma nets, said armatures carrying contacts, sai con-v tacts being in their normal condition when both armatures are unactuated, in their abv normal condition when only one armature is" actuated and again in their normal condition when both armatures are actuated, substantially as'described.

Signed by me at Chicago, county of Cook,

State of Illinois, this 31st day of December WILLIAM W. DEAN.

Witnesses:

E. A. GARLACK, ROBERTLEWIS Aamns. 

